Real-time 3-dimensional transesophageal echocardiography in the evaluation of post-operative mitral annuloplasty ring and prosthetic valve dehiscence

The study of loading mode with in-vitro fatigue testing for mitral annuloplasty ring

To maintain the physiological dynamics of the mitral annulus, mitral annuloplasty rings (MAR) must be flexible. Enhanced flexibility implies decreased resistance to fatigue and potential for fatigue fracture. This study established new methods to test the flexible fatigue life of MAR in-vitro using numerical analysis; the purpose is that the fatigue test could reflect the real stress distribution in-vivo. Based on the conventional test methods (C1, D1), this paper presents a novel test method (C2, D2). Four testing methods for open-end annuloplasty rings (C1, C2) and closed-end annuloplasty rings (D1, D2) were modelled and their stress distribution calculated by finite element analysis. The mean absolute error (Χ) and the Pearson correlation coefficient (Φ) were used to quantify the difference in stress distribution between the loading modes in-vivo and in-vitro. For closed-end annuloplasty rings, the novel test method (D2) is not obvious better than conventional test methods(D1) in duplicating the stress distribution (ΦD1 = 0.88 vs ΦD2 = 0.92). However, the maximum values of stress in the novel test method are closer to the maximum value of stress under in-vivo loading (ΧD1 = 5.2Mpa vs ΧD2 = 4.4Mpa). For open-end annuloplasty rings, the novel test method(C2) is obviously superior to the conventional test method(C1) in duplicating both the stress distribution and the stress peak values of the in-vivo loading (ΦC1 = 0.22 vs ΦC2 = 0.98; ΧC1 = 59.1Mpa vs ΧC2 = 11.0Mpa). The in-vitro loading methods described in this article more closely approximated in-vivo conditions compared to traditional methods. They are simpler to operate, more efficient and can help manufacturers expedite new product development, assist regulatory agencies with product quality oversight.

Novel 3D versus traditional transesophageal echocardiography techniques: Defining differences in the diagnosis of infective endocarditis

BACKGROUND

Despite the availability of current antibiotic and surgical treatment options, infective endocarditis (IE) remains associated with a high mortality rate. Even though two-dimensional (2D) transesophageal echocardiography (TOE) is a major criteria in the diagnosis of IE, it is constrained by the single-plane orientation. Since three-dimensional (3D) TOE provides a comprehensive understanding of the cardiac architecture by allowing for a realistic visualization of the underlying structures in 3D space, it has attracted considerable interest in recent years.

AIM

The purpose of this narrative review is to discuss the advantages and pitfalls of 3D TOE in patients with IE, as well as to address emerging photo-realistic 3D techniques that have the potential to enhance the visualization of cardiac structures in this setting.

RESULTS

According to recent research, 3D TOE acquisitions outperform 2D acquisitions in terms of vegetation identification accuracy and embolism risk assessment. By reporting a variety of findings that are missed with 2D TOE, but which are validated by surgical examination, 3D TOE further improves the ability to identify endocarditis complications on both native and prosthetic valves. In addition to conventional 3D TOE, future developments in 3D technology led to the development of transillumination and tissue-transparency rendering, which may improve anatomical understanding and depth perception. Due to the use of both conventional and novel 3D techniques, there are more patients who require surgical intervention, indicating that 3D TOE may have a clinical relevance on the surgical management.

CONCLUSION

3D TOE might fill the gaps left by 2D TOE in the diagnosis of IE.

Three-dimensional Transesophageal Echocardiography in Infective Endocarditis: What Does It Add?

Infective endocarditis (IE) diagnosis is based on a clinical suspicion supported by consistent microbiological and instrumental data. Evidence of involvement of cardiac valves (native or prosthetic) or prosthetic intracardiac material is a major diagnostic criterion of IE. Transthoracic echocardiography (TTE) is the initial technique of choice for the diagnosis while transesophageal echocardiography (TEE) is recommended in patients with an inconclusive or negative TTE, in patients with high suspicion of IE, as well as in patients with a positive TTE, in order to document local complications. Repeating TTE and/or TEE should be considered during follow-up of uncomplicated IE, in order to detect new silent complications and monitor vegetation size. In the setting of IE, the role of three-dimensional (3D) TEE is increasing; in fact, this technique has also been shown to be useful for the diagnosis of IE and its complications as it allows to obtain infinite planes and volumetric reconstructions. In this review, we will describe the usefulness of 3D-TEE and its added value in the management of IE.

3D echocardiography in mitral valve prolapse

Mitral valve prolapse (MVP) is the leading cause of mitral valve surgery. Echocardiography is the principal imaging modality used to diagnose MVP, assess the mitral valve morphology and mitral annulus dynamics, and quantify mitral regurgitation. Three-dimensional (3D) echocardiographic (3DE) imaging represents a consistent innovation in cardiovascular ultrasound in the last decades, and it has been implemented in routine clinical practice for the evaluation of mitral valve diseases. The focus of this review is the role and the advantages of 3DE in the comprehensive evaluation of MVP, intraoperative and intraprocedural monitoring.

Review of Prosthetic Paravalvular Leaks: Diagnosis and Management

PURPOSE OF REVIEW

Paravalvular leak (PVL) is a relatively uncommon complication associated with prosthetic valve implantation. PVL can occasionally lead to serious adverse consequences such as congestive heart failure, infective endocarditis, and hemolytic anemia. Surgical re-operation carries a high mortality risk.

RECENT FINDINGS

Transcatheter closure therapy provides a viable alternative for the treatment of this disorder with reasonable procedural and clinical success. The recent advent of hybrid imaging modalities has increased procedural success. This article summarizes the pathophysiology, clinical characteristics, and treatment modalities surroundings prosthetic paravalvular leak.

Percutaneous Closure of Mitral Paravalvular Leak: Long-Term Results in a Single-Center Experience

Background: Paravalvular leak occurs in 5–17% of patients following surgical valve replacement, more often in mitral position. The prognosis without treatment is poor. Percutaneous device closure represents an alternative to repeat surgery. The objective of this work is to evaluate the medium and long-term results in the percutaneous closure of PVL in mitral prosthesis. Methods: This observational study is based on a retrospective registry including consecutive mitral PVL cases undergoing percutaneous closure at a single tertiary-care center from April 2010 to December 2020. The safety and efficacy results of the procedure, at 90 days and in the long term, were analyzed. Also, predictors of procedure failure and long-term events were identified. Results: A total of 128 consecutive mitral paravalvular leak closure procedures were included. Technical success was achieved in 115 (89.8%) procedures. The presence of multiple PVLs was the sole factor that independently predicted procedural failure. Median follow-up of our sample was 41.8 months (mean 47.7 ± 35.7 months). Underlying hemolytic anemia as the indication for PVL closure, a recent admission for decompensated HF, and lack of improvement in functional class emerged as consistent predictors of MACE and death during long-term follow-up, while lack of procedural success during the first PVL procedure and chronic kidney disease were also associated with MACE during follow-up. Conclusions: Percutaneous mitral PVL closure displayed high technical and procedural success rates, with an acceptable safety profile, in a high-risk population. Percutaneous mitral PVL closure achieved an improvement in short- and long-term functional class and a reduction of hemolysis in the vast majority of patients. In addition, long-term survival in our study was good, in particular for patients undergoing successful PVL closure procedures.

Mitral Paravalvular Leak: Clinical Implications, Diagnosis and Management

Paravalvular leak incidence after mitral surgical replacement ranges from 7% to 17%. Between 1% and 5% of these are clinically significant. Large PVLs can cause important clinical manifestations such as heart failure or haemolysis. Current guidelines consider that surgical reparation is the gold-standard therapy in symptomatic patients with paravalvular leak. However, these recommendations are based in non-randomized observational registries. On the other hand, transcatheter paravalvular leak closure has shown excellent results with a low rate of complications, and nowadays it is considered the first option in selected patients in some experienced centres. In this review, we summarize the clinical manifestations, diagnosis, procedural details, and results of transcatheter mitral PVL closure.

The Role of Multimodality Imaging in Left-Sided Prosthetic Valve Dysfunction

Prosthetic valve (PV) dysfunction (PVD) is a complication of mechanical or biological PV. Etiologic mechanisms associated with PVD include fibrotic pannus ingrowth, thrombosis, structural valve degeneration, and endocarditis resulting in different grades of obstruction and/or regurgitation. PVD can be life threatening and often challenging to diagnose due to the similarities between the clinical presentations of different causes. Nevertheless, identifying the cause of PVD is critical to treatment administration (thrombolysis, surgery, or percutaneous procedure). In this report, we review the role of multimodality imaging in the diagnosis of PVD. Specifically, this review discusses the characteristics of advanced imaging modalities underlying the importance of an integrated approach including 2D/3D transthoracic and transesophageal echocardiography, fluoroscopy, and computed tomography. In this scenario, it is critical to understand the strengths and weaknesses of each modality according to the suspected cause of PVD. In conclusion, for patients with suspected or known PVD, this stepwise imaging approach may lead to a simplified, more rapid, accurate and specific workflow and management.

Mitral and tricuspid annuloplasty ring dehiscence: a systematic review with pooled analysis

 

OBJECTIVES

Mitral and tricuspid ring annuloplasty dehiscence with consequent recurrent valve regurgitation is a rare but challenging procedural failure. The incidence and predisposing risk factors for annuloplasty ring dehiscence include technical and pathological ones.

METHODS

A systematic database search with pooled analysis was conducted of original articles that only included dehiscence rate of mitral and tricuspid ring in EMBASE, MEDLINE, Cochrane database and Google Scholar, from inception to November 2020. The outcomes included were dehiscence rate in mitral and tricuspid, type of ring implanted, dehiscence rate by pathology and by ring size and shape.

RESULTS

Our search yielded 821 relevant studies. Thirty-three studies met the inclusion criteria with a total of 10 340 patients (6543 mitral, 1414 tricuspid) of which 87 (mitral) and 30 (tricuspid) had dehiscence. Overall, dehiscence rate was 1.43%, diagnosed at a median of 4.5 ± 1.0 months postoperatively. A significant difference in mitral dehiscence rate was found by ring type (semi-rigid 1.86%, rigid 2.32%; flexible 0.43%; P < 0.001). There was no significant difference in rate of dehiscence by ring size (P = 0.067) and shape in mitral (P = 0.281) but there was higher dehiscence rate in ischaemic compared to non-ischaemic mitral regurgitation (3.91% vs 1.63%; P = 0.022). Among tricuspid studies, 9 of 10 studies did not report any dehiscence.

CONCLUSIONS

Although rigid, semi-rigid and flexible annuloplasty rings provide acceptable valve repair outcomes, mitral annuloplasty ring dehiscence is clinically more common among rigid rings. Understanding the multifactorial nature of ring dehiscence will help in identifying the patients at high risk and improve their clinical outcomes.

Normal reference values for mechanical mitral prosthetic valve inner diameters and areas assessed by two-dimensional and real-time three-dimensional transesophageal echocardiography

It was previously observed that two dimensional (2D) Doppler derived and real-time three-dimensional (RT-3D) directly measured valve areas were smaller than reported manufacturer sizes. It may be helpful to obtain the ranges of inner diameters (IDs) and the geometric orifice area (GOA) during evaluation of prosthetic mitral valves. In this study, we aimed to provide reference dimensional parameters of bileflet mitral mechanical prosthetic valves. Patients with recent mitral valve replacement were examined by 2D and RT-3D transesophageal echocardiography (TEE) in the early postoperative period when the presence of pannus overgrowth was unlikely. Measurements of 2D IDs, 3D hinge to hinge (HHD) and edge to edge diameters (EED) and 3D GOA were obtained and compared with reported manufacturer sizes and areas. This study enrolled 126 patients with mitral prosthetic valves (38 ATS, 42 Carbomedics, 46 St. Jude Medical, all bileaflet). The measured 2D and 3D IDs and GOA were significantly smaller than reported manufacturer sizes in the majority of the valve sizes. This RT-3D TEE-guided study provides ranges of reference values for directly measured IDs and GOA of the three most commonly used mechanical mitral prosthetic valve types for the first time in a relatively large series.

Annuloplasty ring dehiscence after mitral valve repair: incidence, localization and reoperation

OBJECTIVES

Mitral valve (MV) annuloplasty ring dehiscence with subsequent recurrent mitral regurgitation represents an unusual but challenging clinical problem. Incidence, localization and outcomes for this complication have not been well defined.

METHODS

From 1996 to 2016, a total of 3478 patients underwent isolated MV repair with ring annuloplasty at the Leipzig Heart Centre. Of these patients, 57 (1.6%) underwent reoperation due to annuloplasty ring dehiscence. Echocardiographic data, operative and early postoperative characteristics as well as short- and long-term survival rates after MV reoperation were analysed.

RESULTS

Occurrences of ring dehiscence were acute (<30 days), early (≤1 year) and late (>1 year) in 44%, 33% and 23% of patients, respectively. Localization of annuloplasty ring dehiscence was found most frequently in the P3 segment (68%), followed by the P2 (51%) and the P1 segments (47%). The 30-day mortality rate and 1- and 5-year survival rates after MV reoperation were 2%, 89% and 74%, respectively. During reoperation, MV replacement was performed in 38 (67%) and MV re-repair in 19 (33%) patients.

CONCLUSIONS

Annuloplasty ring dehiscence is clinically less common, localized more frequently on the posterior annulus and occurs mostly acutely or early after MV repair. MV reoperation can be performed safely in such patients.

Separation anxiety: Extreme dehiscence of a mitral annuloplasty ring

We report a patient admitted with acute pulmonary edema 3 months after mitral valve repair, with no history of inter-current febrile illness. Transesophageal echocardiography (TEE) demonstrated severe mitral regurgitation (MR) and an abnormally positioned annuloplasty ring, suggestive of dehiscence. The extreme extent of ring dehiscence was visualized on 3-dimensional TEE (3D), with near-complete separation of the ring. Strept.Mitis and Cristatus were isolated from the ring following redo mitral valve surgery, confirming endocarditis as the mechanism for dehiscence. This report highlights the additive role and superior ability of 3D TEE in the identification and anatomic delineation of mitral ring dehiscence.

Infective Endocarditis: Echocardiographic Imaging and New Imaging Modalities

Infective endocarditis (IE) is a rare disease with a significant impact and an increasing mortality despite earlier diagnosis and surgical intervention. It is related to several and the main etiological agents are the Gram-positive cocci. The new guidelines propose new diagnostic criteria that consider the potentiality on integrated multimodality imaging. Echocardiography (TTE) plays a key role for the diagnosis of IE and must be performed as soon as IE is suspected. It allows to identify vegetation, abscess, new dehiscence of prosthetic valve and assesses the number, size, shape, location, echogenicity and mobility of vegetations so it also useful for prediction embolic risk. Transesophageal echocardiography (TEE) is indicated when TTE is positive or non diagnostic, in case of suspected complications and when intracardiac device leads are present. We underline the increasing role of three-dimensional (3D) echocardiography in overcoming the limit of 2DTEE in selecting the maximum true diameter of irregular masses (ie, vegetation). We also underline the diagnostic value of multislice computed tomograpfy (MSCT), cerebral magnetic resonance (RMI) and nuclear imaging and also emphasize the emerging role of particular types of endocarditis specially Lead Endocarditis. The aim of this review is to provide an overview of the imaging techniques useful for the diagnosis and identification of any complications. In our opinion, the management of IE is complex, based on an “Endocarditis team “ composed by several specialist and an integrated multimodality imaging is essential for the diagnostic approach.

Mitral annuloplasty ring flexibility preferentially reduces posterior suture forces

Annuloplasty ring repair is a common procedure for the correction of mitral valve regurgitation. Commercially available rings vary in dimensions and material properties. Annuloplasty ring suture dehiscence from the native annulus is a catastrophic yet poorly understood phenomenon that has been reported across ring types. Recognizing that sutures typically dehisce from the structurally weaker posterior annulus, our group is conducting a multi-part study in search of ring design parameters that influence forces acting on posterior annular sutures in the beating heart. Herein, we report the effect of ring rigidity on suture forces. Measurements utilized custom force sensors, attached to annuloplasty rings and implanted in normal ovine subjects via standard surgical procedure. Tested rings included the semi-rigid Physio (Edwards Lifesciences) and rigid and flexible prototypes of matching geometry. While no significant differences due to ring stiffness existed for sutures in the anterior region, posterior forces were significantly reduced with use of the flexible ring (rigid: 1.95 ± 0.96 N, semi-rigid: 1.76 ± 1.19 N, flexible: 1.04 ± 0.63 N; p < 0.001). The ratio of anterior to posterior F_C scaled positively with increasing flexibility (p < 0.001), and posterior forces took more time to reach their peak load when a flexible ring was used (p < 0.001). This suggests a more rigid ring enables more rapid/complete force equilibration around the suture network, transferring higher anterior forces to the weaker posterior tissue. For mitral annuloplasties requiring ring rigidity, we propose a ring design concept to potentially disrupt this force transfer and improve suture retention.

Intracardiac Echocardiography for Structural Heart and Electrophysiological Interventions

PURPOSE OF REVIEW

With an increasing number of interventional procedures performed for structural heart disease and cardiac arrhythmias each year, echocardiographic guidance is necessary for safe and efficient results. The purpose of this review article is to overview the principles of intracardiac echocardiography (ICE) and describes the peri-interventional role of ICE in a variety of structural heart disease and electrophysiological interventions.

RECENT FINDINGS

Both transthoracic (TTE) and transesophageal echocardiography have limitations. ICE provides the advantage of imaging from within the heart, providing shorter image distances and higher resolution. ICE may be performed without sedation and avoids esophageal intubation as with transesophageal echocardiography (TEE). Limitations of ICE include the need for additional venous access with possibility of vascular complications, potentially higher costs, and a learning curve for new operators. Data supports the use of ICE in guiding device closure of interatrial shunts, transseptal puncture, and electrophysiologic procedures. This paper reviews the more recent reports that ICE may be used for primary guidance or as a supplement to TEE in patients undergoing left atrial appendage (LAA) closure, interatrial shunt closure, transaortic valve implantation (TAVI), percutaneous mitral valve repair (PMVR), paravalvular leak (PVL) closure, aortic interventions, transcatheter pulmonary valve replacement (tPVR), ventricular septal defect (VSD), and patent ductus arteriosus (PDA) closure. ICE imaging technology will continue to expand and help improve structural heart and electrophysiology interventions.

Anesthetic challenges in minimally invasive cardiac surgery: Are we moving in a right direction?

Continuously growing patient's demand, technological innovation, and surgical expertise have led to the widespread popularity of minimally invasive cardiac surgery (MICS). Patient's demand is being driven by less surgical trauma, reduced scarring, lesser pain, substantially lesser duration of hospital stay, and early return to normal activity. In addition, MICS decreases the incidence of postoperative respiratory dysfunction, chronic pain, chest instability, deep sternal wound infection, bleeding, and atrial fibrillation. Widespread media coverage, competition among surgeons and hospitals, and their associated brand values have further contributed in raising awareness among patients. In this process, surgeons and anesthesiologist have moved from the comfort of traditional wide incision surgeries to more challenging and intensively skilled MICS. A wide variety of cardiac lesions, techniques, and approaches coupled with a significant learning curve have made the anesthesiologist's job a challenging one. Anesthesiologists facilitate in providing optimal surgical settings beginning with lung isolation, confirmation of diagnosis, cannula placement, and cardioplegia delivery. However, the concern remains and it mainly relates to patient safety, prolonged intraoperative duration, and reduced surgical exposure leading to suboptimal treatment. The risk of neurological complications, aortic injury, phrenic nerve palsy, and peripheral vascular thromboembolism can be reduced by proper preoperative evaluation and patient selection. Nevertheless, advancement in surgical instruments, perfusion practices, increasing use of transesophageal echocardiography, and accumulating experience of surgeons and anesthesiologist have somewhat helped in amelioration of these valid concerns. A patient-centric approach and clear communication between the surgeon, anesthesiologist, and perfusionist are vital for the success of MICS.

Anatomical features of acute mitral valve repair dysfunction: Additional value of three-dimensional echocardiography

Recurrence of mitral regurgitation after mitral valve repair is correlated with unfavourable left ventricular remodelling and poor outcome. This pictorial review describes the echocardiographic features of three types of acute mitral valve repair dysfunction, and the additional value of three-dimensional echocardiography.

A virtual sizing tool for mitral valve annuloplasty

Functional mitral regurgitation, a backward leakage of the mitral valve, is a result of left ventricular growth and mitral annular dilatation. Its gold standard treatment is mitral annuloplasty, the surgical reduction in mitral annular area through the implantation of annuloplasty rings. Recurrent regurgitation rates may, however, be as high as 30% and more. While the degree of annular downsizing has been linked to improved long-term outcomes, too aggressive downsizing increases the risk of ring dehiscences and significantly impairs repair durability. Here, we prototype a virtual sizing tool to quantify changes in annular dimensions, surgically induced tissue strains, mitral annular stretches, and suture forces in response to mitral annuloplasty. We create a computational model of dilated cardiomyopathy onto which we virtually implant annuloplasty rings of different sizes. Our simulations confirm the common intuition that smaller rings are more invasive to the surrounding tissue, induce higher strains, and require larger suture forces than larger rings: The total suture force was 2.2 N for a 24-mm ring, 1.9 N for a 28-mm ring, and 0.8 N for a 32-mm ring. Our model predicts the highest risk of dehiscence in the septal and postero-lateral annulus where suture forces are maximal. These regions co-localize with regional peaks in myocardial strain and annular stretch. Our study illustrates the potential of realistic predictive simulations in cardiac surgery to identify areas at risk for dehiscence, guide the selection of ring size and shape, rationalize the design of smart annuloplasty rings and, ultimately, improve long-term outcomes after surgical mitral annuloplasty. Copyright © 2016 John Wiley & Sons, Ltd.

Paravalvular Regurgitation: Clinical Outcomes in Surgical and Percutaneous Treatments

BACKGROUND

Paravalvular regurgitation (paravalvular leak) is a serious and rare complication associated with valve replacement surgery. Studies have shown a 3% to 6% incidence of paravalvular regurgitation with hemodynamic repercussion. Few studies have compared surgical and percutaneous approaches for repair.

OBJECTIVES

To compare the surgical and percutaneous approaches for paravalvular regurgitation repair regarding clinical outcomes during hospitalization and one year after the procedure.

METHODS

This is a retrospective, descriptive and observational study that included 35 patients with paravalvular leak, requiring repair, and followed up at the Dante Pazzanese Institute of Cardiology between January 2011 and December 2013. Patients were divided into groups according to the established treatment and followed up for 1 year after the procedure.

RESULTS

The group submitted to percutaneous treatment was considered to be at higher risk for complications because of the older age of patients, higher prevalence of diabetes, greater number of previous valve surgeries and lower mean creatinine clearance value. During hospitalization, both groups had a large number of complications (74.3% of cases), with no statistical difference in the analyzed outcomes. After 1 year, the percutaneous group had a greater number of re-interventions (8.7% vs 20%, p = 0.57) and a higher mortality rate (0% vs. 20%, p = 0.08). A high incidence of residual mitral leak was observed after the percutaneous procedure (8.7% vs. 50%, p = 0.08).

CONCLUSION

Surgery is the treatment of choice for paravalvular regurgitation. The percutaneous approach can be an alternative for patients at high surgical risk.

Assessment of Mitral Paravalvular Leakage After Mitral Valve Replacement Using Cardiac Computed Tomography

Background—

The diagnostic performance of cardiac computed tomography (CT) for detection of paravalvular leakage (PVL) after mitral valve replacement has not been investigated in a large population. We aimed to investigate the diagnostic accuracy of CT for diagnosis of mitral PVL using surgical findings as the standard reference and to compare the diagnostic performance of CT with those of transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE).

Methods and Results—

A total of 204 patients with previous mitral valve replacement who underwent cardiac CT were retrospectively included. The presence of mitral PVL was analyzed on CT, TTE, and TEE. In 78 patients who underwent redo-surgery, diagnostic performance for the detection of PVL for CT, TTE, and TEE were compared with surgical findings as the standard reference. The location of mitral PVL on CT and TEE was compared with surgical findings. Mitral PVL was present in 18.1% (37/204) on CT, in 16.2% (32/198) on TTE, and in 42.6% (29/68) on TEE. On the surgical field, PVL was identified in 41.0% (32/78). The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy for detection of PVL were 96.9%, 97.8%, 96.9%, 97.8%, and 97.4% for CT; 81.3%, 95.6%, 92.9%, 87.8%, and 89.6% for TTE; and 96.2%, 95.8%, 96.2%, 95.8%, and 96.0% for TEE. CT and TEE identified the correct location of PVL in 75.9% (22/29) and 85.6% (19/23).

Conclusions—

Cardiac CT may have better diagnostic accuracy compared with TTE for the detection of mitral PVL and may be comparable to TEE for the detection and localization of PVL.

Percutaneous Closure of Paravalvular Leaks: A Systematic Review

Paravalvular leak (PVL) is an uncommon yet serious complication associated with the implantation of mechanical or bioprosthetic surgical valves and more recently recognized with transcatheter aortic valves implantation (TAVI). A significant number of patients will present with symptoms of congestive heart failure or haemolytic anaemia due to PVL and need further surgical or percutaneous treatment. Until recently, surgery has been the only available therapy for the treatment of clinically significant PVLs despite the significant morbidity and mortality associated with re-operation. Percutaneous treatment of PVLs has emerged as a safe and less invasive alternative, with low complication rates and high technical and clinical success rates. However, it is a complex procedure, which needs to be performed by an experienced team of interventional cardiologists and echocardiographers. This review discusses the current understanding of PVLs, including the utility of imaging techniques in PVL diagnosis and treatment, and the principles, outcomes and complications of transcatheter therapy of PVLs.

How Local Annular Force and Collagen Density Govern Mitral Annuloplasty Ring Dehiscence Risk

BACKGROUND

Annuloplasty ring dehiscence is a well described mode of mitral valve repair failure. Defining the mechanisms underlying dehiscence may facilitate its prevention.

METHODS

Factors that govern suture dehiscence were examined with an ovine model. After undersized ring annuloplasty in live animals (n = 5), cyclic force (FC) that acts on sutures during cardiac contraction was measured with custom transducers. FC was measured at ten suture positions, throughout cardiac cycles with peak left ventricular pressure (LVPmax) of 100, 125, and 150 mm Hg. Suture pullout testing was conducted on explanted mitral annuli (n = 12) to determine suture holding strength at each position. Finally, relative collagen density differences at suture sites around the annulus were assessed by two-photon excitation fluoroscopy.

RESULTS

Anterior FC exceeded posterior FC at each LVPmax (eg, 2.8 ± 1.3 N versus 1.8 ± 1.2 N at LVPmax = 125 mm Hg, p < 0.01). Anterior holding strength exceeded posterior holding strength (6.4 ± 3.6 N versus 3.9 ± 1.6 N, p < 0.0001). On the basis of FC at LVPmax of 150 mm Hg, margin of safety before suture pullout was vastly higher between the trigones (exclusive) versus elsewhere (4.8 ± 0.9 N versus 1.9 ± 0.5 N, p < 0.001). Margin of safety exhibited strong correlation to collagen density (R(2) = 0.947).

CONCLUSIONS

Despite lower cyclic loading on posterior sutures, the weaker posterior mitral annular tissue creates higher risk of dehiscence, apparently because of reduced collagen content. Sutures placed atop the trigones are less secure than predicted, because of a combination of reduced collagen and higher overall rigidity in this region. These findings highlight the inter-trigonal tissue as the superior anchor and have implications on the design and implantation techniques for next-generation mitral prostheses.

Utility of Real-Time 3-Dimensional Transesophageal Echocardiography in the Assessment of Mitral Paravalvular Leak

BACKGROUND

Mitral paravalvular leak (PVL) is a potential complication of surgical valve replacement procedures. Real-time 3D transesophageal echocardiography (RT-3DTEE) has emerged as an efficient tool for providing essential information about the anatomy of mitral PVLs compared with 2DTEE findings. The purpose of this study was to evaluate the utility of RT-3DTEE in the assessment of mitral PVLs.

METHODS AND RESULTS

The 3D characteristics of PVLs were recorded and compared with 2D findings. We included 34 consecutive patients with clinical suspicion of mitral PVL in the study. Mitral PVLs were detected in 26 patients (76%); 26 PVLs were identified by 2DTEE and 37 by RT-3DTEE. Moderate or severe mitral regurgitation was present in 23 patients (88%). The most common PVL locations were the septal and posterior regions. The median PVL size measured by RT-3DTEE was 7 mm long×4 mm wide. The median vena contracta of defect measured by 2DTEE and RT-3DTEE was 5 mm and 4 mm, respectively. The median effective regurgitant orifice area of defect measured by RT-3DTEE was 0.36 cm(2). The defect types were "oval" (54%), "round" (35%), "crescentic" (8%) and highly irregular (3%).

CONCLUSIONS

Compared with 2DTEE, RT-3DTEE provided detailed descriptions of the number, location, size and morphology of PVLs, which is essential for planning and guiding the potential corrective techniques. (Circ J 2016; 80: 738-744).

Novel imaging strategies for the detection of prosthetic heart valve obstruction and endocarditis

Prosthetic heart valve (PHV) dysfunction remains difficult to recognise correctly by two-dimensional (2D) transthoracic and transoesophageal echocardiography (TTE/TEE). ECG-triggered multidetector-row computed tomography (MDCT), 18-fluorine-fluorodesoxyglucose positron emission tomography including low-dose CT (FDG-PET) and three-dimensional transoesophageal echocardiography (3D-TEE) may have additional value. This paper reviews the role of these novel imaging tools in the field of PHV obstruction and endocarditis.

For acquired PHV obstruction, MDCT is of additional value in mechanical PHVs to differentiate pannus from thrombus as well as to dynamically study leaflet motion and opening/closing angles. For biological PHV obstruction, additional imaging is not beneficial as it does not change patient management. When performed on top of 2D-TTE/TEE, MDCT has additional value for the detection of both vegetations and pseudoaneurysms/abscesses in PHV endocarditis. FDG-PET has no complementary value for the detection of vegetations; however, it appears more sensitive in the early detection of pseudoaneurysms/abscesses. Furthermore, FDG-PET enables the detection of metastatic and primary extra-cardiac infections. Evidence for the additional value of 3D-TEE is scarce.

As clinical implications are major, clinicians should have a low threshold to perform additional MDCT in acquired mechanical PHV obstruction. For suspected PHV endocarditis, both FDG-PET and MDCT have complementary value.

Current controversies in infective endocarditis

Infective endocarditis is a life-threatening disease caused by a focus of infection within the heart. For clinicians and scientists, it has been a moving target that has an evolving microbiology and a changing patient demographic. In the absence of an extensive evidence base to guide clinical practice, controversies abound. Here, we review three main areas of uncertainty: first, in prevention of infective endocarditis, including the role of antibiotic prophylaxis and strategies to reduce health care-associated bacteraemia; second, in diagnosis, specifically the use of multimodality imaging; third, we discuss the optimal timing of surgical intervention and the challenges posed by increasing rates of cardiac device infection.

Infective endocarditis presenting initially with ileus complicated by dehiscence of annuloplasty ring

BACKGROUND

Infective endocarditis (IE) on an annuloplasty ring dehiscence is uncommon after mitral valve repair.

CASE PRESENTATION

A 53-year-old man underwent mitral annuloplasty with a 24-mm ring for posterior mitral valve prolapse. He underwent repeat valve repair for recurrent mitral valve regurgitation 4 years later. He was re-hospitalised complaining of vomiting, nausea, general fatigue and left abdominal pain 2 months later, and presented with low-grade fever, leukocytosis and an elevated blood concentration of C-reactive protein. An abdominal computed tomography scan showed multiple embolisms in the liver, kidney and spleen. Transoesophageal echocardiography revealed mitral annuloplasty ring dehiscence and vegetations consistent with IE. The infected annuloplasty ring and vegetations were surgically excised. Blood cultures grew coagulasenegative staphylococcus aureus, consistent with the excised mitral valve histology. The postoperative course was uneventful, without recurrence of IE.

CONCLUSIONS

Embolic ileus as initial manifestation of IE is rare and might confuse the diagnosis and delay its management. Gastrointestinal signs and symptoms may be the initial manifestations of systemic embolization from infective endocarditis. Transoesophageal echocardiography effectively identified the presence of vegetations and mitral annuloplasty ring dehiscence.

Echocardiographic assessment of prosthetic valves

Echocardiographic evaluation of prosthetic valves is similar in many respects to evaluation of native valve disease. However, there are some important differences. First, there are several types of prosthetic valves with different fluid dynamics for each basic design and differing flow velocities for each valve size. Second, the mechanisms of valve dysfunction are somewhat different from those for native valve disease. Third, the technical aspects of imaging artificial devices, specifically the problem of acoustic shadowing, significantly affect the diagnostic approach when prosthetic valve dysfunction is suspected. Fourth, transcatheter aortic valve implantation (TAVI) has rapidly expanded in recent years. Echocardiography plays an essential role in identifying patients suitable for TAVI and providing intra-procedural monitoring, and is the modality for post-procedure follow-up. Both an understanding of the basic approach to echocardiographic evaluation and detailed knowledge of the specific flow dynamics for the size and type of prosthesis in an individual patient are needed for appropriate patient management.

[Catheter-based closure of paravalvular leaks: "Plug the hole"]

Paravalvular leak (PVL) is a relatively rare, but serious complication occurring in up to 10% of patients after prosthetic aortic valve replacement and in up to 17% of patients after prosthetic mitral valve replacement. Up to 5% of patients will present with symptoms of congestive heart failure or mechanical haemolytic anaemia due to PVL and need further surgical or interventional treatment. Surgical repair is often technically challenging and carries a high mortality and morbidity risk. Catheter-based closure of PVL has emerged as an alternative approach especially for patients with relevant comorbidities at high surgical risk. Interventional closure of PVL is a complex procedure, which needs to be performed by an experienced team of interventional cardiologist, echocardiographer and anesthesiologist. To date available clinical results are promising showing low complication rates and high technical or clinical success rates of catheter-based closure of PVL (60-90%). Compared to surgical closure of PVL lower mortality rates (30-days mortality rate: 4,6%) have been documented in patients treated by catheter-based closure of PVL in clinical practice. Therefore interventional closure seems to be a promising option, which need to be discussed with every symptomatic patient suffering from PVL prior to therapeutical decision making. To date only sparse clinical data is available regarding indication and clinical outcome of patients undergoing catheter-based PVL in clinical practice. Therefore interventional closure of PVL should be limited to experienced interventional cardiologist at present. All patients treated should further be enrolled into a clinical registry to evaluate the safety and efficacy of catheter-based closure of PVL in clinical practice.

Incidental necropsy finding of a quadricuspid aortic valve

Quadricuspid aortic valve is a rare congenital cardiac malformation often associated with abnormal valve function. In this article, we present a case of quadricuspid aortic valve only diagnosed at the time of post-mortem examination.

Obstructed bi-leaflet prosthetic mitral valve imaging with real-time three-dimensional transesophageal echocardiography

Real-time three-dimensional transesophageal echocardiography (RT3D-TEE) can provide unique visualization and better understanding of the relationship among cardiac structures. Here, we report the case of an 85-year-old woman with an obstructed mitral prosthetic valve diagnosed promptly by RT3D-TEE, which clearly showed a leaflet stuck in the closed position. The opening and closing angles of the valve leaflets measured by RT3D-TEE were compatible with those measured by fluoroscopy. Moreover, RT3D-TEE revealed, in the ring of the prosthetic valve, thrombi that were not visible on fluoroscopy. RT3D-TEE might be a valuable diagnostic technique for prosthetic mitral valve thrombosis.

Echocardiographic Assessment of Heart Valve Prostheses

Patients submitted to valve replacement with mechanical or biological prosthesis, may present symptoms related either to valvular malfunction or ventricular dysfunction from other causes. Because a clinical examination is not sufficient to evaluate a prosthetic valve, several diagnostic methods have been proposed to assess the functional status of a prosthetic valve. This review provides an overview of echocardiographic and Doppler techniques useful in evaluation of prosthetic heart valves. Compared to native valves, echocardiographic evaluation of prosthetic valves is certainly more complex, both for the examination and the interpretation. Echocardiography also allows discriminating between intra- and/or peri-prosthetic regurgitation, present in the majority of mechanical valves. Transthoracic echocardiography (TTE) requires different angles of the probe with unconventional views. Transesophageal echocardiography (TEE) is the method of choice in presence of technical difficulties. Three-dimensional (3D)-TEE seems to be superior to 2D-TEE, especially in the assessment of paravalvular leak regurgitation (PVL) that it provides improved localization and analysis of the PVL size and shape.

Suture forces in undersized mitral annuloplasty: novel device and measurements

PURPOSE

To demonstrate the first use of a novel technology for quantifying suture forces on annuloplasty rings to better understand the mechanisms of ring dehiscence.

DESCRIPTION

Force transducers were developed, attached to a size 24 Physio ring, and implanted in the mitral annulus of an ovine animal. Ring suture forces were measured after implantation and for cardiac cycles reaching peak left ventricular pressures (LVP) of 100, 125, and 150 mm Hg.

EVALUATION

After implantation of the undersized ring to the flaccid annulus, the mean suture force was 2.0±0.6 N. During cyclic contraction, the anterior ring suture forces were greater than the posterior ring suture forces at peak LVPs of 100 mm Hg (4.9±2.0 N vs 2.1±1.1 N), 125 mm Hg (5.4±2.3 N vs 2.3±1.2 N), and 150 mm Hg (5.7±2.4 N vs 2.4±1.1 N). The largest force was 7.4 N at 150 mm Hg.

CONCLUSIONS

The preliminary results demonstrate trends in annuloplasty suture forces and their variation with location and LVP. Future studies will significantly contribute to clinical knowledge by elucidating the mechanisms of ring dehiscence while improving annuloplasty ring design and surgical repair techniques.

Incremental value of 3-D transesophageal echocardiographic imaging of the mitral valve

Transesophageal echocardiography provides excellent visualization of the posteriorly located mitral valve. Over the last decade, 3-dimensional transesophageal echocardiography (3D TEE) has emerged as an exciting imaging modality, particularly of the mitral valve. The current generation matrix array technology allows the operator to perform 2D and 3D imaging with a single transducer. 3D TEE affords the unique ability to view the mitral valve and its surrounding structures "en face" in real time (RT), and provide contextual anatomical guidance during surgical and transcatheter interventions. Additionally, offline quantification has made significant contributions to our mechanistic understanding of the normal and diseased mitral valve, and alterations induced by therapeutic intervention such as surgical repair. This review will address recent advances in the incremental role of 3D TEE in mitral valve imaging.

Catastrophic mitral prosthesis dehiscence diagnosed by three-dimensional transesophageal echocardiography

In emergency situations, real-time three-dimensional transesophageal echocardiography (RT 3-dimensional TEE) may provide unique anatomic insights on prosthetic valves when two-dimensional imaging is inconclusive. We report the case of a 76-year-old woman, in cardiogenic shock, who had undergone mitral valve replacement 3 months ago. RT 3-dimensional TEE revealed almost total, catastrophic prosthesis dehiscence following infective endocarditis, the prosthesis being perpendicular to the normal mitral plane. Corrective surgery was not feasible, and the patient died shortly after admission. Although the outcome was unfortunate, RT 3-dimensional TEE helped rapidly reach a definitive diagnosis, essential for decision-making. Three-dimensional TEE should be used as a complementary technique in difficult cases.

Mitral Valve Annuloplasty Ring Dehiscence Diagnosed Intraoperative With Real-Time 3D Transesophageal Echocardiogram

Mitral annular calcification (MAC) is often a result of the accumulation of lipids around the annulus, which can lead to degeneration and calcification of the valve. Multiple risk factors have been associated with the progression of MAC and life-threatening complications such as the early mitral valve annuloplasty dehiscence. Our case describes the different risk factors for annuloplasty dehiscence in a patient with severe MAC, as well as the importance of its early recognition intraoperatively with 3D transesophageal echocardiography.

Three-Dimensional Echocardiography: Advancements in Qualitative and Quantitative Analyses of Mitral Valve Morphology in Mitral Valve Prolapse

Degenerative mitral valve disease (MVD) is the leading cause of organic mitral regurgitation (MR), one of the most common valvular heart disease in western countries. Substantial progresses in the surgical treatment of degenerative MVD have improved life expectancy of patients with significant MR. However, prognosis, surgical decision and timing of surgery strongly depend on the accurate characterization of mitral valve (MV) anatomy and pathology and on the precise quantification of MR. Three-dimensional (3D) echocardiography, a major technological breakthrough in the field of cardiovascular imaging, provides several advantages over two-dimensional (2D) imaging in the qualitative and quantitative evaluations of MV apparatus. In this review, we focus on the contribution of this new modality to the diagnosis of degenerative MVD, the quantitative assessment of MR severity, the selection and monitoring of surgical and percutaneous procedures, the evaluation of procedural outcomes. The results of a systematic and exhaustive search of the existing literature, restricted to real-time 3D echocardiography in adults, are here reported.

A rare case of hemolytic anemia in a pediatric patient due to ring dehiscence after mitral valve repair: utility of real-time three-dimensional imaging and management

A rare case of hemolytic anemia in a 3-year-old child due to mitral valve ring dehiscence is described. The dehiscence of mitral valve ring was diagnosed utilizing real-time three-dimensional echocardiography. The patient subsequently underwent reoperation with successful resolution of hemolysis after replacement of the ring.

Real-time three-dimensional transesophageal echocardiography in the assessment of mechanical prosthetic mitral valve ring thrombosis

Although 2-dimensional (2D) transesophageal echocardiography (TEE) is the gold standard for the diagnosis of prosthetic valve thrombosis, nonobstructive clots located on mitral valve rings can be missed. Real-time 3-dimensional (3D) TEE has incremental value in the visualization of mitral prosthesis. The aim of this study was to investigate the utility of real-time 3D TEE in the diagnosis of mitral prosthetic ring thrombosis. The clinical outcomes of these patients in relation to real-time 3D transesophageal echocardiographic findings were analyzed. Of 1,263 patients who underwent echocardiographic studies, 174 patients (37 men, 137 women) with mitral ring thrombosis detected by real-time 3D TEE constituted the main study population. Patients were followed prospectively on oral anticoagulation for 25 ± 7 months. Eighty-nine patients (51%) had thrombi that were missed on 2D TEE and depicted only on real-time 3D TEE. The remaining cases were partially visualized with 2D TEE but completely visualized with real-time 3D TEE. Thirty-seven patients (21%) had thromboembolism. The mean thickness of the ring thrombosis in patients with thromboembolism was greater than that in patients without thromboembolism (3.8 ± 0.9 vs 2.8 ± 0.7 mm, p <0.001). One hundred fifty-five patients (89%) underwent real-time 3D TEE during follow-up. There were no thrombi in 39 patients (25%); 45 (29%) had regression of thrombi, and there was no change in thrombus size in 68 patients (44%). Thrombus size increased in 3 patients (2%). Thrombosis was confirmed surgically and histopathologically in 12 patients (7%). In conclusion, real-time 3D TEE can detect prosthetic mitral ring thrombosis that could be missed on 2D TEE and cause thromboembolic events.